This invention relates to the handling of a ribbon or tape. More specifically, it relates to the transport of ribbon or tape from the ribbon box to the print point in a typewriter, dot matrix printer, or serial impact printer.
A typewriter as well as other forms of printers typically includes provision for relative motion between the impact means and the print receiving means so that the characters may be printed along a line. Commonly, in older style typewriters, the print receiving medium is moved with respect to the character elements which remain stationary. The paper and platen move with respect to the frame of the machine while the character elements are substantially fixed. In modern typewriters and printers the print elements are typically moved with respect to the platen. Since the mechanical operations are the limiting factor in the speed of such machines, a reduction in the inertia of moving parts allows an increase in speed. Thus, it is desirable to move the print element rather than the platen since the former is generally lighter in weight.
It is also desirable that the printing ribbon which passes between the print receiving means and the character elements be stored in a stationary position with respect to the frame of the machine again allowing a reduction in the inertia of moving parts. This has led to the use of flexible leaders which guide the printing ribbon between a stationary ribbon cartridge and movable print point. In order for these leaders to function properly it is necessary that they bend in one direction only so that the ink side of the ribbon will not contact the leader where the leader forms an enclosed channel. It is also important to reduce frictional load between the ribbon and the leader. Furthermore, the leader must be flexible enough in the vertical direction to allow for movement in that direction when multi-colored ribbons are used. Also, the leader must provide good ribbon tracking. Finally, the leader must protect the ribbon from operator contact and be easy to install.